'92 K2500 Suburban Refurb...

[markhuntsville]

Ooops - I jump ahead of myself - first let me update you on the TBI rebuild we performed.

I decided that it was time to rebuild the TBI - the engine performance was terrible and throttle response was even worse.

I went to Autozone and got the kit, including fuel pressure regulator diaphram and removed the TBI.

Here, David is cleaning the body with carb/choke cleaner and various tools;


This is what the regulator internals looked like (YUCK!)


And here's the TBI after most of the cleaning, top side;


Bottom side;


Rear view assembly;


Front view assembly;


And re-installed on the engine;
(kinda makes the engine look pretty dirty..)


So, now for the results - WOW! What a difference! All I can say is that if you haven't rebuilt your TBI, and you've got any issues like throttle lag, then DO IT! It was easy, and the results were HUGE! The engine runs better, starts easier, and pulls better. All this improvment for only $45 and a few hours of time.

I am so happy with this, that I decided I want to do the 'UltimateMods' for the TBI. I found a complete TBI on Craigslist for $40 shipped and will be working on heavily modifying it with every mod listed. Of course, this unfortunately has to wait until the heads are taken care of... now on to the heads...

[markhuntsville]

OK - now on to the heads...

I tore into the engine last Wed night, spent ~2 hours then, and another ~3 hours Thursday night to get the heads removed so I could drop them off at the local head service shop. They 'thought' they could get them back to the same day (Friday), but they could get them done. Also took the exhaust manifolds for surfacing the mating surface. They also removed 2 broken bolts in the exhaust manifold-to-downpipe flange and 2 broken bolts in the heads.

The REALLY good news is the motor HAS been changed by some previous owner. It has an IROC Z28 'L98' motor, which is rated at 230hp, 330ftlb torque - of course that is with the TPI, so I'm sure it's not quite that on the TBI. But this is good news since the L98 heads are better than the aweful TBI heads and have the capability of being enhanced (porting, larger valves, etc) to really make them good. I've left them stock for now, since I'm still on a tight budget.

Here's the engine immediately after the heads were removed;
(a fair amount of sludge in the lifter valley, typical for 150K+ miles)


Here's the cylinder that appears to have had the worst coolant leak (#2);
(note the 'clean' look of the top of the piston)


Here's the cleaned lifter valley;




After cleaning the top-end of the motor, I decided that we should go ahead and drop the oil pan to clean the bottom-end. This will give us the chance to beat out the dents in the oil pan AND replace the oil pump. The oil pan looked like someone took a baseball bat to it.

Picked up the heads today (Monday). They machined the face of the exhaust manifolds (no exhaust leaks here!);


Here's a snapshot of the head casting;


I've ordered the Edelbrock 3704 TBI Performer intake, roller tip rockers, and a few other goodies that you'll see when the engine gets put back together.

[bigtfw2000420]

i would buy some headers why u are there u got it all apart

[94383Z71]

wow guys, I wish I had the ability to tear into my own motor like that. Sure, I did engines in shop, but they'd never been run before. Nothing like this

great stuff guys, really. So this is a 350?

EDIT: saw the sig

[ROCK_KRAWLER]

It has been a lot of work but will be worth it in the long run!

and one more AWESOME comment on the duratracs! I pulled up to the entrance to the park(long gravel loose hill climb) put the suburban in 4low and walked all over the muddy parking lot and hill while pulling the jeep on the trailer. it did awesome! I cant wait to use it this winter on my weekend long trips. Should be a lot better sleeping in the suburban than a tent in 30 below temps!

[markhuntsville]

Headers are on the long-range plan, but will have to wait a while... budget is really blown having to get all this done. The head work ended up being ~$340. (this included several small other things like removing broken bolts from the exhaust manifolds, 1 broken accessory bolt from each head, surfacing the exhaust manifolds, etc) The heads look great!

All the mail-order parts came in yesterday and today! And I picked up the remainder of the parts today at AutoZone. Unfortunately, it supposed to rain all day tomorrow, so we'll be cleaning and painting parts tomorrow. I'm going with Hammered Silver for the oil pan and front engine brackets. Gonna paint the bolts black. We plan on getting right on it Saturday morning and going until it runs!

Started tearing down the 'project' TBI lat night. Will upload pics next time of the teardown.

Pulled the oil pump out and it looks new. It has a Melling PN: (M55HV) on the side which inidicates a High-Volume oil pump. It did have a 'wad' of crap in the screen, not big, just about the size of an eraser from a pencil...

[markhuntsville]

Started putting it back together...

Heads installed;


Air cleaner lid becomes hardware holder;


Closeup of lifter valley;
(after cleaning)


David torqing the heads;


Following the sequence;


A preview look with the valve covers sitting;


Got the instake mounted;


Drivers side exhaust manifold was a real bear to get aligned!


Hole in the firewall where the new gauges and addtional wiring are run;
(grommet to be added)


Added a 'T' fitting for the oil pressure gauge, but this may be a problem with the distributor as the distributor baseplate interferes with the electric pressure sender...


Mechanical temp sender location on the passenger side head;


One more view of the motor;


Gotta LOVE that 'Made in USA' sticker on the Edelbrock manifold!!

It's going a LOT slower than I had hoped..originally planned on having it running today, but the 2 hours I spent on the drivers exhaust manifold really slowed me down.

Still have a long list of thing still be to be done, but I'm going to hit it hard tomorrow night to see if we can get it fired up.

[bigtfw2000420]

u need to lose that fram filter and go buy a wix i dont trust cardboard to filter my oil

[m3gumby]

stumbled upon this build. love the work you've done. did the carpet get completely cleaned?

[markhuntsville]

Originally Posted by m3gumby

stumbled upon this build. love the work you've done. did the carpet get completely cleaned?

Thanks! It's been a LOT of work, we're proud of what we've been able to do with it.

Carpet - Well, let's say it's acceptable; considering this is an off-road tow rig. It's going to get dirty, so we're not real concerned about the appearance. Plus the Husky Liners (floor mats) hide most all the remaining 'spots'.

Nobody is grossed out with the carpet now like when we brought it home! And is smells ok now.

[moman]

Hey man you've got an awesome rig there, helluva job cleaning her up. I'd buy it in a second for what you paid.

Now that your boy is talking about being in the back instead of a tent, I'm getting really mad at my GF for making me sell my G20. Maybe I'll find a old 'Burb and bring it home and see what she says now.

[90Accord]

the difference is crazy

[markhuntsville]

OK - been working a little each night, when it's not raining! Seems like we're getting rain every other day here...

Got the Distributor installed - after re-doing the oil pressure sender 'setup'. I installed a 'T' to run both the factory oil pressure sender for the dash gauge, and a seperate manual oil pressure gauge (as part of a set of aftermarket gauges). This ended up being quite complicated as the initial installation with the original oil pressure sender mounted on top of the 'T' interfered with the distributor. So I had to put the original sender in the side of the 'T' and the aftermarket gauge connected to the top.

Here's a pic, a quick;ly taken shot before the rain gets here (again!);
You can see the electric sender in the rear, laying down and pointing to the passenger side and the white hose for the manual gauge coming up from behind the throttle cable bracket.


Another interference is the MAP sensor (is it the MAP?);


And the final interference is the coil, which I'm going to cut down the bracket to 'lower' the coil closer to the intake. (no pic yet)

So here's a couple of pics of the motor as it sits... still have quite a few parts to re-install...




I had to go to NAPA to get correct radiator hoses and temp sending units. The AutoZone radiator hoses were close, but would have had the hose pinched where it was being bent to fit. The NAPA hoses fit perfect. AutoZone said one of the temp senders wasn't 'available', yet NAPA had both and were exactly right. Once again, proving you get what you pay for - i.e. NAPA is more expensive than AutoZone, and I have to keep remembering that for 'specialized' parts, sometimes it's beter to get the NAPA part.

David got the new Alpine SPS-406 front speakers installed today as well, so the factory original speakers are finally gone!

We're heading to Talladega in the morning (if the rain moves out in time) to see the Truck race and camp overnight. We'll then see the Cup race Sunday.

Sure would have been nice to get the 'Mater going to take to the race.... I guess we'll get back to work Monday evening...

[Gopedxr]

Let us know how much better it runs : ) Nice work man!

[markhuntsville]

IT'S ALIVE!

Well, she's running again, and seems to run very well!

I did have the distributor in 180deg out (crap! I thought I carefully brought it to TDC when installing the distributor) - simple correction and it fired right up!

Throttle response is smooth, although a little loud with the 14" open element air cleaner.

We've got some 'cleanup' to do with wiring, get some new pics and I'll post them later this weekend.

[94383Z71]

wow. pretty intense stuff yall been doin, and I like it

[RWSZ71]

Great looking suburban, well done.

[markhuntsville]

Finally - sunshine and a weekend at the same time to get some updated pics.

We've been driving the Suburban around town quite a bit and really like the updates. The electric fans made a huge difference in power (the K2500 fan clutch was 'engaged' most of the time due to the 'towing' package).

Here's a few new pics;
Electic fans installed and working on the wiring;


Ended up cutting the bottom of the fan shroud off and using the top 1/3 to cover up the radiator and support it;


Website for the fan mfg:
http://www.ffdynamics.com/index.htm
(not real impressive website, but they have a good product at a REALLY good price - the installation kit leave a little to be desired, but if you're handy, you can get it installed easily)









Only thing left is I still need to 'tweak' the timing a little - I set it exactly at 0 deg advance and it's got a little lag to it, so I'm going to bump it up to about 5 deg advance to see how it runs.

Still need to get back to work on the modified Throttle Body.

Then we'll hook the computer up to it to start collecting data for a custom chip, which should really wake up the motor.

[94383Z71]

man, you guys do some amazing work, really.

Thanks for the link to the efans, I've been thinking about those for awhile. Pricey, but I hear they're worth it, plus they look better and free up a bit of power

[markhuntsville]

Originally Posted by 94383Z71

man, you guys do some amazing work, really.

Thanks for the link to the efans, I've been thinking about those for awhile. Pricey, but I hear they're worth it, plus they look better and free up a bit of power

Thanks for the compliments - we try to do it right - within the budget...(or continuously modified budget!)

Yes, I was the same way about the electric fans (do I REALLY want to spend that much $), so when we replaced the radiator, I simply replaced the stock fan clutch with a new one - big mistake! The new clutch was even tighter than the original one and the fan spun even harder, thus sucking more power from the engine.

So, when we had the head gasket failure, I decided electric fans had to be done to make the most of the enhancements (I just couldn't see leaving the mechanical fan on the motor). For the $, these fans are a really good buy. You CAN get some from a junkyard and coble something together, but my concern was longivity. With us towing, I didn't want to have a fan failure on the road and leave us stranded, or worse yet, overheating the motor that we just put a lot work and $ into....

David took the Suburban on a short trip up to a OHV park today, towing a Rhino & a 4-wheeler as a preliminary test, so far, so good. We did have the thermostat housing leak a little this morning, but the bolts needed tightening, so hopefully, that's all it needed.